1) Field of the Invention
The present invention relates to a stereoscopic image display apparatus.
2) Description of the Related Art
A stereoscopic image display apparatus for displaying a stereoscopic image having a three-dimensional impression on a two-dimensional screen is disclosed, for example, in Japanese Patent Kokai No. 2000-115812. As shown in FIG. 1 of the accompanied drawings, the stereoscopic image display apparatus disclosed in the above-mentioned Japanese Patent Kokai No. 2000-115812 uses liquid crystal panels 1 and 2, and a half mirror 3. As illustrated in FIG. 1, an observer can simultaneously observe a light beam 4 transmitted through the half mirror 3 and a light beam 5 reflected by the half mirror 3. The light beam 4 is emitted from a displayed image on the liquid crystal panel 1, and the light beam 5 is emitted from a displayed image on the liquid crystal panel 2. Accordingly, the two displayed images can be observed by the observer as if those images are respectively positioned forward and backward. In this instance, when a brightness balance of the two liquid crystal panels is properly adjusted, the apparatus provides the observer with an image having a three-dimensional impression.
Another technique, for example, shown in FIG. 2 of the accompanied drawings is also widely known in the art as an alternative technique of the conventional stereoscopic image display apparatus. The stereoscopic image display apparatus shown in FIG. 2 provides the observer with an image having a three-dimensional impression on the principle that two organic electroluminescence panels are combined as a front and a back panel, which thus synthesizes a light beam 9 from the front panel 7 having light transmissibility and a light beam 8 from the back panel 6, thereby providing the observer with overlapped images which are respectively displayed on the panels.
The technique shown in FIG. 1 requires an optical arrangement of the two display panels and the half mirror. This arrangement requires accurate positioning of the constituent elements to a level of a single pixel. Accordingly, the apparatus becomes complicated and large. The technique shown in FIG. 2 requires the front panel which is made from a material providing light transmissibility. Accordingly, a manufacturing method is complicated, which causes problems such as an increased manufacturing cost and a reduced product yield. Furthermore, a part of the light beam from the front panel may go toward the back panel, which causes a reflection of the display image of the front panel on the back panel.